Your lawn’s health relies on many factors. Of course feeding, weeding and watering contribute to healthy grass, but you may not know that mower height belongs on that list as well, affecting much more than basic aesthetics.
Cutting grass at the proper height encourages new growth, which leads to a denser lawn. And density comes with many benefits. A dense, healthy lawn withstands pests better and discourages weeds, requiring less chemical intervention. A denser lawn also withstands drought and wear better, helping protect the soil and prevent erosion.
Cutting your lawn at the improper height, however, can cause damage. Remember in school when you learned about photosynthesis? Grass needs enough blade height to turn sunlight into energy.
When the blades are cut too short, the grass can’t convert enough sunlight to sustain a vigorous root system. A less vigorous root system absorbs fewer nutrients and less water, ultimately restricting growth and inviting pests, weeds, erosion and other unwelcome issues.
Variety of Heights
To determine the optimal mowing height for your lawn, first identify the type of grass growing in your yard. Each variety grows best within a slightly different height range.
When to Go High
Letting grass grow freely without regular mowing not only upsets the neighbors, it also inhibits growth and invites disease, fungi and rot. However, some situations warrant a slightly higher mower setting.
- When unrelenting Southern summers bring an onslaught of hot, dry weather, raise your mower deck half an inch higher to help relieve your lawn of stress.
- Grass in shady areas may struggle to get enough light. A higher mower setting leaves behind more blade surface to soak up sunrays and encourage growth.
- For warm season grasses that go dormant in winter, raise your mower height in the fall to strengthen your lawn for the winter.
- To battle crabgrass, keep to the higher side of the optimal height range. Longer grass shades the soil and helps discourage germination of seeds from crabgrass and other pesky weeds.
Obey the 1/3 Rule
One mowing rule is universal, no matter the variety of lawn — never cut more than one third of the grass height in a single mowing. The sudden change in height upsets the crucial balance between the grass blades and roots, injuring the lawn.
Occasionally the weather and your busy schedule may conspire against you, allowing your lawn to get out of hand—it happens. Resist the urge to cut the extra growth in a single mowing. Instead, maintain your usual schedule and cut only one third of the height at each mowing until your grass returns to the optimal range.